1. Field
One or more embodiments relate to a composite binder for a battery, and an anode and a battery including the same.
2. Description of the Related Technology
Lithium batteries have high voltage and high energy density and thus, are used in various applications. For example, electric vehicles (hybrid electric vehicle (HEV) or plug-in hybrid electric vehicle (PHEV)) need to operate at high temperature, need to be charged or discharged with a large amount of electricity, and are used for a long period of time. Accordingly, they require lithium batteries having excellent discharge capacity and lifespan characteristics.
Carbonaceous materials have a porous structure and thus, during charging and discharging, they undergo less volumetric change. However, due to the porous structure of carbon, a battery using such carbonaceous materials has a small capacitance. For example, certain graphite forms having high crystallinity may theoretically have a capacity of 372 mAh/g.
A metal that is alloyable with lithium may be used as a negative active material having higher electric capacitance than the carbonaceous materials. For example, a metal that is alloyable with lithium may be Si, Sn, Al, and the like. However, metal that is alloyable with lithium may easily deteriorate and thus its lifespan characteristics may be poor. For example, Sn particles may be repeatedly aggregated and crushed when charging and discharging are repeatedly performed and thus, Sn particles may be electrically insulated.
Accordingly, there is a need to develop a binder that improves lifespan characteristics of a lithium battery by accepting and/or suppressing a volumetric change of these non-carbonaceous negative active materials.